A client can go full-screen without telling the mud. This is perhaps pointless, but it will work. The mud doesn't care. What will happen is this: all the text will be on the left, leaving a big black void on the right. Even if the client told the mud, it's just "Hey, I can now support longer line lengths."

If you're going to do this, disable wrapping in your mud of choice, assuming you can, and use the wrapping of the client. I don't know of any muds nowadays that prevent you from changing line length and all that, honestly. Mushclient does do fullscreen, and on older versions of windows, any client that runs in a console window can be made full-screen as well: alt+enter should do it.

A client can go full-screen without telling the mud. This is perhaps pointless, but it will work. The mud doesn't care. What will happen is this: all the text will be on the left, leaving a big black void on the right...Mushclient is the one-client-fits-all solution in my opinion.

Never liked Mushclient. Too mushy. But the point is, with a couple of changes in your font selection and your rows and colums (as you said all MUDs allow this) then it doesn't matter if the client and MUD talk. Who cares? You have a full screen, you have text wrapping and you have the font you like no matter what client you are using without the MUD server doing jack. All in under 30 seconds.